If you're a nuclear plant owner who needs to haul slightly radioactive steam generators across the United States, there's only one answer: a 192-wheel, 400-foot-long road train that tops out at 15 mph. This is just the front half.

The steam generator is one of four from the San Onofre Nuclear Generating Station in southern California that must be swapped for newer models. Because they contain radiation levels similar to Homer Simpson's lunchbox, they must be hauled to a nuclear waste site in Clive, Utah, an 832-mile trip of about 21 days. And since each weighs 380 tons, regular trucks and train cars can't handle the load.

The truck's builder, Perkins Specialized Transport, took nearly two years to construct the 48-axle behemoth. While the California Highway Patrol will escort the trailer for the entire trip, and its exact departure dates are a secret, it's not like you can hide a road train about two-thirds the height of the Washington Monument behind a few Kias.

As for worries from bystanders, Southern California Edison says you'd have to sit in front of it for a spell to get the same amount of radiation as in a dental X-ray. Remember that warning when Clive, Utah, suffers its first outbreak of zombies.